mfb said:There is no meaningful way to express the expansion of space as a kinetic object of objects inside.
Unrelated to that, the total size of the universe is unknown (it could even be infinite). You can ask for the observable universe.
The average energy density (for regular matter, dark matter and dark energy) is an interesting number.Philosopha said:What can I ask for the observable universe? Considering there is no meaningful way to express the expansion as a kinetic object.
You can associate the acceleration of the expansion with an energy density (dark energy). You do not have to, however.The observable universe is what I'm after. So is there any energy associated with its expansion or not? - Because I was told there is just the way I did it is wrong...
Mechanical energy is a type of energy that is possessed by an object due to its motion or position. It can be either kinetic energy, which is the energy of motion, or potential energy, which is the energy stored in an object's position or shape.
Mechanical energy is not directly related to the self energy of the universe. However, the concept of self energy refers to the total energy of the universe, including all forms of energy such as mechanical, chemical, thermal, and so on.
The law of conservation of energy states that energy cannot be created or destroyed, only transferred or transformed from one form to another. This applies to mechanical energy as well. It can be converted from one form to another, but the total amount of mechanical energy in a closed system remains constant.
Mechanical energy plays a significant role in everyday life. It powers machines and vehicles, allowing us to travel and perform tasks more efficiently. It is also present in the food we eat, as our bodies use mechanical energy to move and function.
Some examples of mechanical energy include a swinging pendulum, a rolling ball, a spinning top, and a moving car. Other examples include a bouncing basketball, a vibrating guitar string, and a falling object. Essentially, any object that is in motion or has the potential to move has mechanical energy.